One of Britain's biggest charities, an international land-mine-clearing organization that worked with Princess Diana and is supported by her son Prince Harry, pays tens of thousands of dollars a year to send its chief executive's children to private boarding schools, The Telegraph reports.

Halo Trust leader Guy Willoughby's three younger children attend institutions that charge more than $45,000 a year for boarders. The charity also covered private-school fees for his elder daughter, now attending college.

Halo rose to prominence when Princess Diana made a much-photographed visit to an Angolan mine field being cleared by the group shortly before her death in 1997. Prince Harry is a patron of the Scotland-based organization, which reported income of more than $42.7-million last year, including a $6.6-million government grant.

The school payments were criticized by members of Parliament who are investigating rising executive compensation at major U.K. charities. Mr. Willoughby defended the practice, saying his children attend boarding school because he and his wife are frequently abroad for work and that government agencies subsidize private education for diplomatic and defense officials posted overseas.